Production of seamed metal tubes



Jan.30,1968 H.DE CQRTA 6,366,767

PRODUCTION OF SEAMED METAL TUBES Filed July 27', 1964 I 4 Sheets-Sheet 1FIG. 2a

Flt 3.1a-

INVENTOR HUBERT 0s CORTA BYW /W ATTORNEYS Filed July: 27, 1964PRODUCTION OF SEAMED METAL TUBES 4 Sheets-Sheet 2 l NvE-N TOR HUBE RT DECORTA ATTORNEY S Jan. 30, 1968 H.DE CORTA PRODUCTION OF SEAMED METALTUBES 4 Sheets-Sheet 5 Filed July 27, 1964 INVENTOR HUBERT DECORTAATTORNEYS H. DE CORTA O I 3,366,767

Jan. 30, 1968 PRODUCTION OF SEAMED METAL TUBES 4- Sheets-Sheet 4 F ledJuly 27, 1964 MHNHC mm mm 60 Y INVENTOR HUBE RT DE CORTA BY/ V 0ATTORNEYS Uite rates ate" 3,366,767 PRGDUCTION F SEAMEI) METAL TUBESHubert de Corta, Fontenay-Sous-Bois, Seine, France,

assignor to Lorraine-Escaut, Paris, France, a company of France FiledJuly 27, 1964, Ser. No. 385,164 Claims priority, application France,July 29, 1363, 9 032 4 Claims. 61. 219-8.5)

ABSTRACT 6F THE DISCLOSURE Installations already exist in which seamedmetal tubes are made from flat material. Such installations are,generally speaking, laid out in the form of a straight production line,a band of sheet metal being introduced at one end of it and a successionof seamed tubes emerging at the other. From one end of the line to theother, these installations may comprise a shaping device, in which theunwinding band of metal is first shaped to form an open tube, a Weldingposition, where the open tube is welded, the edges of the metal beingbrought together, and a gauging mill in which the tube, which may firsthave been heated, is reduced to its correct size, after which it can bedivided into whatever lengths are desired.

Such installations, already known to technologists, op eratesatisfactorily and can commonly run at speeds in the neighbourhood of180 feet a minute.

Various ways of increasing the amount of seamed tubes produced may beconsidered. One can try to raise the speed at which the tubes passthrough the installation, but the technical limits of such animprovement are very soon reached. Another possible approachand this iswhat is aimed in the present invention-is to attempt to design a plantcapable of turning out several parallel runs of tubing simultaneously.

In more precise terms, the invention relates to an installation for thecontinuous production of seamed metal tubes, having as itsdistinguishing feature the fact that, from a single band of metal, itcan cut, shape, Weld, reduce to size and finaly divide off several runsof tubing travelling along separate parallel paths. From the point wherethe single band of metal is fed in, this installation comprises, in itsessentials, a cutting position, where the metal is cut into parallelhorizontal strips; a positioning unit, in which these strips aresuitably spaced apart and where certain of them may be turned over sothat the cutting burrs on all the strips may turn the same way; amultiple former, the paths through which are spaced in the same way asthe strips, the shaping being independently regulated for each path; amultiple welding unit; a unit for cleaning up the weld from the outsideof the various tubes; possibly a multi-path gauging unit; and, iinally,a shearing unit.

Such an installation, made up of units each having 11 paths, naturallytakes up less space from side to side than would the combination of nsingle-path monotube units, by virtue of the judicious positioning ofthe various members for the various paths.

The purpose of turning over certain of the strips cut from the originalsingle band is to ensure that all the cut- 3,366,767 Patented Jan. 30,1968 ice ting burrs resulting from cutting the band into strips are, forexample, turned upwards. In this way, during the shaping of the variousruns of tubing, in the course of which the side edges of the differentstrips are curved inwards and upwards, the cutting burrs thus come tolie on the inside of the various tubes that are being formedsimultaneously.

The welding of the tubes may be carried out by any known method, such asinduction or contact welding. It is also possible to incorporate in theinstallation whatever tube cooling or heating arrangements are requiredfor applying any particular method of welding and of finishing the tubesafter welding.

The description that follows, in conjunction with the accompanyingdrawings, which are primarily intended to serve as examples, willexplain clearly how the invention can be put into effect. Here it shouldbe stated that the invention is essentially concerned with theproduction of an odd number of tubes from a single original length ofsheet metal. In view of the possible technical complications arisingfrom a large number of tubes, preference has been given to thesimultaneous production of three runs. Reference will be made to theaccompanying drawings, in which:

FIGURES 1a, 1b and 1c are diagrammatic plan views of the feed,intermediate and delivery sections of the installation, respectively;and

FIGURES 2a, 2b and 2c are side elevations correspond ing respectively toFIGURES 1a, 1b and 10.

At the feed end of the plant, a band 1 of sheet metal runninghorizontally, is continuously fed forward and suitably presented to theequipment by guide members 2. The band 1 passes through a cutting unit3, in which shears 3a divide it into three strips, B1, B2 and B3, ofwhich B1 and B3 lie outside the strip B2, one on either side. Any burrsthat are inevitably formed in course of shearing are turned upwards(standing out from the upper face) on the strip B2 and downwards(standing out from the underside) on the strips B1 and B3. Since, aswill be seen later, the shaping of all the strips is done by curvingtheir edges inwards and upwards, it is desirable that the cutting burrson all the strips should be turned upwards, so that they may come on theinside of the tubes when these are formed. This means that both stripsBland B3 must be turned over before going to the forming unit. Inaddition to this, all three strips B1, B2 and B3 need to be suitablyspaced apart in parallel lines before going to the forming unit.

For turning over the strips B1 and B3 and for obtaining the properrelative spacing between the strips B1, B2 and B3, a turning andpositioning unit 4 is employed. This consists essentially of two guiderollers, 4a and 4b, mounted on vertical spindles. Strip B1, which makescontact in a vertical plane with the guide roller 4a, thus passes intothe vertical as it comes level with this guide roller, beyond which itcontinues turning over until its. two faces have been transposed. Thesame happens to the strip B3, which, after making contact in a verticalplane with the guide roller 4b, finally has its two faces transposed.After passage through the unit 4, not only do the three strips B1, B2and B3 carry their cutting burrs on their upper faces, but they are alsoall spaced at the same relative distance e apart.

The strips B1, B2 and B3 are now ready to enter the forming unit 5,travelling in three separate parallel paths centered on the lines A1, A2and A3 respectively (FIG. lb).

A forming (or rolling) unit 5 is providedwhich, as with the other unitsin the production line, will not be described in detail here-differsfrom monotube units of this kind only in being designed to form threetubes at a time, all its shaping and guiding members being provided intriplicate and judiciously laid out so as to keep the transversedimension as small as possible and well below three times thecorresponding dimension of a monotuoe forming unit. The unit comprises areceiving guide system 6 (FIG. 2b) and a certain number of verticalcages such as that numbered 7, in which the strips B1, B2 and B3 passbetween forming rollers, which apply substantially vertical shapingpressure, and horizontal cages such as that numbered 8, in which thestrips B1, B2 and B3 pass between forming rollers that applysubstantially horizontal shaping pressure. The strips are thereby formedinto tube blanks T1, T2 and T3. It should be noted that for thehorizontal cage 8, for example, the pair of rollers 62, which is shapingthe middle tube blank T2, and the pairs of rollers G1 and G3, whichserve to shape blanks T1 and T3, are longitudinally offset in astaggered relationship, to reduce the side-to-side width of the unit.

Similarly, the terminal pairs of forming rollers, F1, F2 and F3, at thedelivery end of the forming unit, corresponding respectively to blanksT1, T2 and T3, have their axes oifset in a staggered relationship alongspaced parallel lines, such an arrangement also making it possible forthe final shaping pass on each of the three tubes to be independentlyregulated.

On leaving forming unit 5, the tubes are guided independently by guides9a and enter a welding unit 9, where they are welded at points s1, s2and s3 respectively, these points being staggered longitudinally, withthe aid of weld rollers S1, S2 and S3. The welding may be carried out bythe radio-frequency method, for example, by induction or by contact,power being supplied through a transformer 10.

Upon leaving the welding unit, the tubes go to a trimming unit, wheretrimmers 11, 12 and 13 finish off the weld on the outside of the tubes.These trimmers are characteristically staggered longitudinally.

The formed tubes T1, T2 and T3 next pass in FIGS. and 2c into a coolingunit, 14 (consisting of sprinkler arrays, for example), and then to agauging unit comprising a certain number of vertical housings such asthat numbered 15, horizontal housings such as that numbered 16 and Turkshead straightening units such as that numbered17. The rollers of thehorizontal housing 16 and some of the rollers of the straightening units17 are longitudinally oifset in a staggered relationship. Finally, thethree runs of tubing T1, T2 and T3 pass to a dividing head 13, wherethey are cut by shearing means into lengths as required.

It will be noted that the description of the various component units ofthe installation has not covered such details as the mechanical drive ofeach unit. Such details are readily available to those skilled in theart and do not form part of the invention as such, which is primarilyconcerned with the combination of a mechanism H for shearing the initialsingle band of metal with the subsequent turning and positioning ofstrips B1, B2 and B3 and the judicious laying out of the various partsof the plant so as to reduce the overall space occupied to the minimum.

A further point to note is that the installation conforming to theinvention makes possible either the simultaneous production of tubeswhich are preferably of the same diameter or the simultaneous productionof tubes of diflierent diameters.

What is claimed is:

1. An installation for the continuous production of a plurality ofWelded metal tubes from a single metal band, said installationcomprising in combination and in the stated order;

(a) feeding means for feeding a single metal band to a cutting location,

(b) cutting means at said cutting location operable to cut said singlemetal band into a plurality of metal strips,

(c) positioning means operable to locate each of said plurality of metalstrips in a spaced parallel relationship and to turn over alternatestrips so that burrs formed by said cutting means face in the samedirection for all of said plurality of metal strips,

(d) separate forming means associated with each strip independently,with rollers to form a tube blank from one said plurality of metalstrips associated with said separate forming means, at least some ofsaid separate forming means with rollers, offset from each other in astaggered relationship along spaced parallel lines,

(e) separate welding means offset from each other in a staggeredrelationship along spaced parallel lines associated with each of saidtube blanks independently to weld said tube blanks,

(f) separate cleaning means offset from each other in a staggeredrelationship along spaced parallel lines, associated with each of saidwelded tubes independently to clean the weld of the associated tube, and

(g) shearing means operable to cut each of said associated tubes inpredetermined lengths.

2. The installation of claim 1 wherein said separate welding means is aradio frequency welding means jointly controlled.

3. The installation of claim 1 wherein said cutting means is operable tocut said single metal band into three metal strips.

4. The installation of claim 1 including separate gauging meansassociated with each of said cleaned welded tubes independently withrollers, at least some of said separate gauging means with rollersoffset from each other in a staggered relationship along spaced parallellines, said separate gauging means disposed between said separatecleaning means and said shearing means.

References (Iited UNITED STATES PATENTS 759,480 5/1904 Shifley 72-1292,631,361 3/1953 Wallace 29477.7 3,230,336 1/1966 Gueugnier 2l9-8.5

RICHARD M. WOOD, Primary Examiner.

l. G. SMITH, Assistant Examiner.

